well i suppose i should just put it out there this will hopefully be going on my 06 2500HD chevy 6.0. i had thoughts originally to supercharge it but at 6000 bucks for a universal roots supercharger that won't work with my gen 3 heads i said forget it. i know i could cram 8 psi into it safely without changing pistons or anything else. i would expect around a 100 horse gain with the right setup and tuning. i am more looking for gains above 2500 rpm. the one downfall to LS engines is the peak torque is around 4000 which is hardly usable while towing. Very few aftermarket companies make power adders specifically for my truck that are reasonably priced.
I figure if i could buy a decent turbo for around 5-800 with wastegate, upgrade the injectors, make exhaust and intake tubing, and buy a used intercooler, then tune it for less then 3000 i'd be happy.